Specifications: Color: Black Bluetooth Version: V5.0 Support: Hfp 1.7, Hsp 1.2, A2dp 1, Avrcp1.6, Spp 1.2 And Pbap 1.0 Charging Voltage: Dc 5v Microphone Sensitivity: -42db Working Temperature: -10-50 °c Frequency Response Range: 20-20000hz Sensitivity: 120db+/-5db Transmission Distance:10m Charging Time:about 1 Hours Accumulated Battery Life: About 220 Hours Headphone Battery Capacity: 50mah Charging Box Battery Capacity: 3500mah